The Mechanism and Clinical Application of Transcutaneous Electrical Nerve Stimulation in The Treatment of Neuropathological Pain after Spinal Cord Injury

Transcutaneous electrical nerve stimulation (TENS), functioning as a prominent non-invasive neuromodulation technique, has been widely utilized as a critical adjuvant treatment for managing neuropathic pain (NP) following spinal cord injury (SCI). This article systematically reviews the underlying physiological mechanisms of TENS in alleviating NP after SCI, alongside its recent clinical application progress. Extensive studies have demonstrated that the profound analgesic effect of TENS may be intricately linked to the activation of thick myelinated Aβ fibers, which subsequently enhances the segmental inhibition of the spinal cord. Furthermore, TENS is implicated in promoting the release of endogenous opioids, regulating the descending pain inhibition pathways, significantly reducing central sensitization, and modulating complex neuroimmune responses within the central nervous system. In terms of clinical application, empirical evidence indicates that both high-frequency and low-frequency TENS modalities can substantially reduce the intensity of NP after SCI, thereby markedly improving the overall quality of life for affected patients. Despite these promising outcomes, notable individual differences in therapeutic efficacy persist, and the optimal stimulation parameters and standardized intervention protocols have yet to be universally established. The existing body of evidence firmly supports TENS as a safe, accessible, and highly effective non-pharmacological option for treating NP after SCI. Nevertheless, comprehensive, large-sample, high-quality, and long-term follow-up clinical trials are still urgently required to further optimize targeted treatment strategies and to fully elucidate the underlying neuroplasticity mechanisms driving long-term pain relief.